package org.eclipse.rally.plugin.utils;

import org.apache.axis.encoding.Base64;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StringBufferInputStream;
import java.io.UnsupportedEncodingException;

import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;


public class StreamDesEncrypter {
    Cipher ecipher;
    Cipher dcipher;
    byte[] salt = {
            (byte) 0xA9, (byte) 0x9B, (byte) 0xC8, (byte) 0x32, (byte) 0x56,
            (byte) 0x35, (byte) 0xE3, (byte) 0x03
        };

    // Iteration count
    int iterationCount = 19;

    // Buffer used to transport the bytes from one stream to another
    byte[] buf = new byte[1024];

   public  StreamDesEncrypter(String passPhrase) {
        try {
            // Create the key
            KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt,
                    iterationCount);
            SecretKey key = SecretKeyFactory.getInstance("PBEWithMD5AndDES")
                                            .generateSecret(keySpec);
            ecipher = Cipher.getInstance(key.getAlgorithm());
            dcipher = Cipher.getInstance(key.getAlgorithm());

            // Prepare the parameter to the ciphers
            AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt,
                    iterationCount);

            // Create the ciphers
            ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
            dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
        } catch (java.security.InvalidAlgorithmParameterException e) {
        } catch (java.security.spec.InvalidKeySpecException e) {
        } catch (javax.crypto.NoSuchPaddingException e) {
        } catch (java.security.NoSuchAlgorithmException e) {
        } catch (java.security.InvalidKeyException e) {
        }
    }

    StreamDesEncrypter(SecretKey key) {
        // Create an 8-byte initialization vector
        byte[] iv = new byte[] {
                (byte) 0x8E, 0x12, 0x39, (byte) 0x9C, 0x07, 0x72, 0x6F, 0x5A
            };
        AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);

        try {
            ecipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
            dcipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

            // CBC requires an initialization vector
            ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
            dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
        } catch (java.security.InvalidAlgorithmParameterException e) {
        } catch (javax.crypto.NoSuchPaddingException e) {
        } catch (java.security.NoSuchAlgorithmException e) {
        } catch (java.security.InvalidKeyException e) {
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        try {
            // Generate a temporary key. In practice, you would save this key.
            // See also e464 Encrypting with DES Using a Pass Phrase.
            //        SecretKey key = KeyGenerator.getInstance("DES").generateKey();

            // Create encrypter/decrypter class
            //     StreamDesEncrypter encrypter = new StreamDesEncrypter(key);
            StreamDesEncrypter encrypter = new StreamDesEncrypter("pASSW0RD123");

            // Encrypt
            String s = "Sreidhar.k@gloabllogic.com/Tech8092";

                encrypter.encrypt(new IOString(s).getInputStream(),
                      new FileOutputStream("ciphertext"));
           
            IOString ios = new IOString();
            // Decrypt
            encrypter.decrypt(new FileInputStream("ciphertext"),
                ios.getOutputStream());
            System.out.println("Decrypted: " + ios.getString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void encrypt(InputStream in, OutputStream out) {
        try {
            // Bytes written to out will be encrypted
            out = new CipherOutputStream(out, ecipher);

            // Read in the cleartext bytes and write to out to encrypt
            int numRead = 0;

            while ((numRead = in.read(buf)) >= 0) {
                out.write(buf, 0, numRead);
            }

            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void decrypt(InputStream in, OutputStream out) {
        try {
            // Bytes read from in will be decrypted
            in = new CipherInputStream(in, dcipher);

            // Read in the decrypted bytes and write the cleartext to out
            int numRead = 0;

            while ((numRead = in.read(buf)) >= 0) {
                out.write(buf, 0, numRead);
            }

            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 8-byte Salt
    public String encrypt(String str) {
        try {
            // Encode the string into bytes using utf-8
            byte[] utf8 = str.getBytes("UTF8");

            // Encrypt
            byte[] enc = ecipher.doFinal(utf8);

            // Encode bytes to base64 to get a string
            return Base64.encode(enc);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    public String decrypt(String str) {
        try {
            // Decode base64 to get bytes
            byte[] dec = Base64.decode(str);

            // Decrypt
            byte[] utf8 = dcipher.doFinal(dec);

            // Decode using utf-8
            return new String(utf8, "UTF8");
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }
}
